He daren't go there because it is very dangerous.他不敢去那兒，因為那兒很危險。2．dare用作實義動詞時，有時態(tài)和人稱的變化，用do, does或did來構(gòu)成否定句或疑問句。She didn't dare to say a word, did she?她一句話也不敢說，是嗎？六、have to的用法have to意為“不得不”，有時態(tài)、人稱和數(shù)的變化，其否定形式為don't/doesn't/didn't have to。It's too late. I have to go home now.天色太晚了，我現(xiàn)在得回家了。You don't have to finish the work now.你沒有必要現(xiàn)在完成這項工作。【點津】 have to和must的區(qū)別：have to表示一種客觀的需要，而must表示一種主觀的需要。此外，must還表示“偏要”“非得”的意思。I have to attend an important meeting this afternoon.今天下午我不得不參加一個重要的會議。I must clean the room because there are too dirty.因為太臟了，我必須要打掃房間。七、had better的用法had better意為“最好；應(yīng)該”，后跟動詞原形，常用來提出建議，或表示迫切的希望、警告等，語氣較強。其中動詞had沒有人稱或數(shù)的變化。had better的簡略式為：'d better，否定式為：had better not。She'd better get here soon or she'll miss the opening ceremony.她最好快點到這兒來，否則她會錯過開幕式的。